Update runtime files.
diff --git a/runtime/doc/usr_41.txt b/runtime/doc/usr_41.txt
index 162eb9d..80b7e38 100644
--- a/runtime/doc/usr_41.txt
+++ b/runtime/doc/usr_41.txt
@@ -1,4 +1,4 @@
-*usr_41.txt*	For Vim version 8.2.  Last change: 2022 May 13
+*usr_41.txt*	For Vim version 8.2.  Last change: 2022 May 21
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -1923,6 +1923,8 @@
 If you split your plugin into parts, you can use `import` and `export` to
 share items between those parts.  See `:export` for the details.
 
+More information about writing plugins is in |usr_51.txt|.
+
 ==============================================================================
 
 Next chapter: |usr_42.txt|  Add new menus